Advanced Materials Research Vols. 139-141

Abstract: A water absorbent wood hydrogel was prepared with the wood and acrylamide using glutaraldehyde as crosslinker. The structure of wood-based hydrogel was charactered by FTIR spectra. The monomer ratio, the amount of glutaraldehyde, the behavior of pH-sensitivity and salt-sensitivity of the wood hydrogel were studied in this paper. The results are as follows: The water absorption and grafting yield of wood-based hydrogel decreased with the increasing of wood content. The water absorption of wood-based hydrogel decreased with the crosslinker content increasing, the grafting yield increases with the crosslinker content increasing. The water absorption of wood-based hydrogel has strong sensitivity in pH value of 3.0 ~ 11.0 solution. At acidic and alkaline larger environment, the hydrogel shows a larger water absorption, and the smallest swelling ratio was obtained in pH7.0 buffer solution. The wood-based hydrogel shows stable behavior in different concentrations of sodium chloride solution.

Abstract: Programmable logic controller (abbr. PLC) is essential for automation in modern industry. In many colleges, it is also an important course for automation major. Currently, PLC is monopolistic technique with foreign company. Simulation of PLC has become popular scheme for substitute to real PLC. Virtual PLC is a kind of common scheme. Otherwise, virtual PLC is unfavorable of practical training for student. The thesis spread out exposition for a new simulation system, which consists of virtual PLC platform and a printed circuit board. The virtual PLC platform had been programmed under visual C++ by authors. It is a graphical programming tool, and is an interpretive routine too. Based on MCU, the board is developed for communication between virtual PLC and real control objects. The simulation system has been tried out. As an example, traffic light control of intersection shows feasibility and effectiveness.

Abstract: In the machine manufacturing industry, CNC machine tools possess many advantages and have gradually become the leading machine tools to replace the ordinary machine tools. According to their processing usages, they can be divided into two kinds: general CNC and NTC. With the automatic tool change device consisting of tool magazine and mechanical arm, the latter can complete the most, if not all, processings of workpieces in a clamping. According to the instruction to select tools from the digital control system, the tools in the tool magazine can be located to the position for tool change, which is called automatic tool selection. Automatical tool selection can be implemented at random and sequentially. This paper focuses on random tool selection in ATC tool magazine controlled by Mitsubishi FX2N PLC series.

Abstract: In this paper, a new nonlinear amplification principle based on chaotic theory is proposed. Firstly, according to the basic properties of chaotic systems, such as the sensitivity of the initial conditions and the one-to-one correspondence between chaotic orbit and the initial value, we established the nonlinear enlarge model based on the parabola map. Then, after we studied the nonlinear amplification of the parabola map, and the binary relationship between input and output, we achieved the simulation of the nonlinear amplification with common signals. Thirdly, we compared the result of linear amplification with nonlinear amplification; and discussed the advantages and disadvantages of nonlinear amplification under real situation. Finally, we get the conclusion that the weak signal amplification principle which is based on parabola map has superiority. It can reduce the noise while enlarging the useful signal. In other words, it can improve the signal to noise ratio.

Abstract: To satisfy the performance test of the high power hydraulic pump, a test-bed is developed in this paper. The parameters, the sign of the control and the data of the state are concluded. The test-bed employs the virtual instrument technique and PXI bus structure as well as M series data acquisition apparatus, it can measure the important performance parameters, such as pressure, flow, torque, speed and temperature; then we deal with and analysis these data. During the testing procedure it can realize automatic control, such as regulating the flow, pressure and so on. During the measuring and controlling, we can also monitor the state of the test-bed and give an alarm, such as over temperature or pressure.

Abstract: Because of the poor reconfigurability of the existing test resource models and the faultiness of the intelligent modeling methods in automatic test system, the modeling method based on Multi-Agent was studied. By analyzing the characters of test resources, the test resource models were classified as device model, adapter model and configuration model. The typical test resource model based on Multi-Agent with three layers and five agents was built. The structure and function of system management agent, model reconfiguration agent, function management agent, channel control agent and function realization agent in the model were analyzed. Then its application in Intelligent Virtual Instrument was introduced. This model based on Multi-Agent has good reconfigurability and intelligence, and it can be used to build the general-purpose and intelligent automatic test system.

Abstract: To solve the problem of deformation measurement for spatial complex tubular joints, a non-contact three-dimension optical method is proposed. Firstly, some artificial targets are pasted on the deformation area before loading. Then the three-dimension coordinates of those targets are calculated by three-dimension reconstruction technique including collinear equation, image orientation based on the coplanar equation, direct linear transform, epipolar geometric constraint and bundle adjustment. Finally, each single deformation stage is aligned to the basic stage, by tracking and comparing the three-dimension coordinates of the homonymous artificial targets, the deformation vectors are obtained. The precision evaluation experiments prove that the proposed measurement system could achieve accuracy of 0.1mm/m. Real scale model experiment shows that the proposed method could fulfill the efficiency and accuracy requirement in three-dimension deformation measurement of the spatial complex tubular joints. In addition, this method has the advantage of non-contact.

Abstract: This paper aimed to use a novel optic interferometric fringe projection to measure the three-dimensional shape of small object with high resolution. In this method, the projecting fringe pattern, which has a sinusoidal density distribution, good contrast and equal spacing, is generated by a spherical wave incident into a triangle-section prism. Project the fringe onto the subject under test, the image of the deformed fringe pattern modulated by object surface is captured by a high-speed CMOS camera and processed by the Fourier Transform technique to extract the phase distribution which is related to height information. An experimental system is set to conduct 3-D shape measurement and the result shows the validity of the proposed method. The projecting system is simple and compact, which helps to realize the integration and miniaturization of the system.

Abstract: This paper aims to simulate the sound field of rectangular small enclosure excited by panel loudspeaker with FEM. Firstly, in order to testify the fluid-structure interaction theory in the field of acoustics calculation, coupled modal and uncoupled modal of loudspeaker and air were established. Result of harmonic response analysis shows that the vibration amplitude of uncoupled case is larger than the coupled case. The result just is in harmony with the fact. So when modeling the sound field, fluid-structure coupling should be taken into account. Secondly, for more accurate sound field simulation, different from most researchers’ modeling method that supposing the vibrating plate’s boundary of the loudspeaker is simply supported, this paper provide a more practical way that the boundary is elastic supported. The comparison shows that the resonance of air in enclosure is more severe under elastic boundary on condition of same driving force. Thereby the sound pressure is higher.

Abstract: For accurate inspecting the micro-topography defects of IC chip, characteristic recognizing method of topography defects based on image projection transformation and energy optimization modeling is presented. First the topography conjugate images have been obtained by high-definition CCD cameras from different space positions, and then we extracting the relative positions of several selected IC defect characteristic-points, through establishing the relationship of image projecting transformation these point’s absolute three-dimensional coordinates can be calculated and determined, with energy optimization modeling the controlling curves are fitted, and then the defect topography in each enclosing spatial region which constituted by these controlling curves is structured. Mathematical characteristics are established according to the topography model, after training and adjusting BP network repeatedly the topography defects can be characteristic-recognized, and the recognizing results are gotten. In this experiment the performance comparison and analysis are implemented in several typical recognizing methods of image characteristic, which prove this new method’s accuracy and reliability and provide new idea for following IC chip’s precise detection.